I actually just added some LED lights to my planted tank. I started a thread in the planted tank section and I am going to post some pictures of my plants to see if the LEDs work well for growing plants. I am pleased so far but the jury is still out on growing plants, only been in the tank 3 days. If you go to that thread you can see what I bought and the website has a lot of info making some promising claims about growing plants with them. That is how they are really marketed. I do know that all LEDs are not equal and you need more than high watts or lumens, needs to be the right wavelengths, par requirements and a lot of other sciencey things. So hopefully my experiment will answer this question for some other people as the ones they claim are good enough for plants are not cheap. I paid about 130 for a 12 watt 5 led strip. They do add a cool shimmer effect when there is water movement.

I use some MR11's on my Fluval Edge. The LEDs are actually encouraging plant growth. I have a C. Wendtii that appears to be doing well, my H. Tenellum just sent out a few runners and the Marsilea Spp... well I think it'd to better if I kept better control on my duck weed.

The issue with my LED setup is mostly the fluval edge design. With only two MR11 sockets for LEDs, the coverage of the LEDs is not very ideal *and* the lighitng is in the very very low range.